This bug actually occurred first in version 1.8.1 pre3. In my world I have different locations which are connected by nether portals. Each portal (overworld and nether) is placed at the exact matching x and z coordinates (For example: overworld portal x = 80, z = 80; nether portal x = 10, y = 10). When going through any portal, the player is not placed right inside or in front of the corresponding portal. Instead he is moved a few blocks away, causing the player to be sometimes teleported into walls, which can lead to wall suffocation and even death.